While a few Twitter users misinterpreted it as a botched Photoshop job, some people offered an explanation that makes a lot of sense: It's an optical illusion. Kardashian West's arm simply looks misshapen because of the shadow cast by her breast.

Despite the confusion over Kardashian West's arm being settled, some people turned their attention to Kourtney Kardashian's seemingly missing arm.

If you look closely, however, you can see Kourtney's elbow just behind Kendall Jenner, who is resting her head on her arm.